Chinese police have detained 22 people for making drug capsules using a toxic raw material produced from scrap leather, state media said, in the latest in a string of product safety scandals.

Police in the eastern province of Zhejiang found the suspects allegedly made and sold capsules with excessive levels of chromium after using industrial gelatin made from discarded leather, the Xinhua News agency said late Monday.

Chromium, which has several industrial uses including leather tanning, can cause cancer.

China has been hit by a series of product safety scandals, often involving food or pharmaceuticals, despite government pledges to improve supervision, and public outrage over lax controls and official corruption is on the increase.

According to Xinhua, at least half of the people detained worked for capsule makers in Zhejiang's Xinchang county, a major production base.

Police and government departments of Zhejiang and Xinchang county were not immediately available for comment.

According to the report, the industrial gelatin used to make the capsules came from other factories in the northern province of Hebei and the eastern province of Jiangxi.

In another twist to the scandal, police also detained a factory owner in Hebei for allegedly setting fire to his own plant to destroy evidence of making industrial gelatin, Xinhua said in a separate report Tuesday.

Song Xunjie, manager of the Xueyang Glair Gelatin Factory, is said to be a supplier to companies across the country, it added.

The government's State Food and Drug Administration (SFDA), the industry regulator, on Sunday also suspended sales of 13 types of drugs confirmed to have excessive levels of chromium.

The case is the latest in a long series of product safety scandals.

In November last year, authorities busted a gang that produced and sold fake medicine -- some made of animal feed -- arresting 114 suspects and seizing more than 65 million counterfeit tablets.

And Zheng Xiaoyu, former head of the SFDA, was executed in 2007 for accepting $850,000 in bribes in exchange for granting approval for hundreds of medicines, some later found to be dangerous.